add .mergify.yml

.mergify.yml

@@ -0,0 +1,14 @@
+pull_request_rules:
+  - name: automatic merge
+    conditions:
+      - base=master
+      - '#approved-reviews-by>=1'
+      # - 'status-success=ci/circleci'
+    actions:
+      merge:
+        method: merge
+        # method: rebase
+        # rebase_fallback: merge
+        # strict: smart
+      dismiss_reviews: {}
+      delete_head_branch: {}